Overview of Exchange Web Forms
An Exchange Web form is a Web page that is registered in the Exchange store. Exchange Web forms consist of the following pieces:
- Form registration
- Form renderer
- Microsoft® Internet Explorer 5 Dynamic HTML (DHTML) views and behaviors
Understanding the Exchange Web Form Process
The following diagram illustrates the Exchange Web form process. The numbered items show the steps of the process and are explained in the text that follow the diagram.
- The user requests information from a computer running Microsoft Exchange Server 2003 by opening a folder or a message. This request is processed by Microsoft Internet Information Services (IIS).
- IIS invokes an Internet Server Application Programming Interface (ISAPI) dynamic-link library (DLL), the same DLL that the Exchange store uses to process all WebDAV requests. The ISAPI.dll checks the Exchange store form registry to see if a matching form registration exists.
- A form registration is an item in the
Exchange store that
consists of a series of form definition fields. These fields specify properties
to be matched, such as browser type and language, and processing information.
These fields specify which form to render and how to render the form.
Information read from the HTTP request header is processed and compared against
browser information that is stored in the Browsecap.ini file to determine browser
capabilities. The ISAPI.dll uses a best-fit comparison with the form registry
to determine the form to display to the user.
If a matching form registration is found, then the computer checks the form registration to see how to render the form. If a matching registration does not exist, then the requested information is rendered with a standard form.
- The form registry passes two parameters to the form renderer.
- formurl Field - Value in formurl the parameter
- An Exchange Web form can be rendered in three ways:
- As a custom ASP page
- As an HTML page using the form renderer
- As an ASP page using the form renderer
At this point, data items are bound to the form. Data items can be messages, contacts, calendaring, custom properties, and so forth.
- The form renderer returns the form and form data to IIS.
- IIS returns the Web page to the requesting Web browser. Depending on the capabilities of the Web browser, data is bound on the server or the client.